Drug Information for PIPRACIL (piperacillin for injection) For Intravenous and Intramuscular Use (Wyeth Pharmaceuticals, Inc.): ADVERSE REACTIONS

PIPRACIL is generally well tolerated. The most common adverse reactions have been local in nature, following intravenous or intramuscular injection. The following adverse reactions may occur:

Local Reactions: In clinical trials thrombophlebitis was noted in 4% of patients. Pain, erythema, and/or induration at the injection site occurred in 2% of patients. Less frequent reactions including ecchymosis, deep vein thrombosis, and hematomas have also occurred.

Gastrointestinal: Diarrhea and loose stools were noted in 2% of patients. Other less frequent reactions included vomiting, nausea, increases in liver enzymes (LDH, AST, ALT), hyperbilirubinemia, cholestatic hepatitis, bloody diarrhea, and pseudomembranous colitis. The onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment. (See WARNINGS.)

Hypersensitivity Reactions: Anaphylactic/anaphylactoid reactions (some leading to shock and fatalities) have been reported. (See WARNINGS.)

Rash was noted in 1% of patients. Other less frequent findings included pruritus, vesicular eruptions, and positive Coombs tests.

Other dermatologic manifestations, such as erythema multiforme, urticaria, toxic epidermal necrolysis and Stevens-Johnson syndrome, have been reported.

Renal: Elevations of creatinine or BUN, renal failure and interstitial nephritis have been reported.

Central Nervous System: Headache, dizziness, fatigue, and seizures have been reported.

Hemic and Lymphatic: Hemolytic anemia, agranulocytosis, pancytopenia, prolonged bleeding time, reversible leukopenia, neutropenia, thrombocytopenia, and/or eosinophilia have been reported. As with other β-lactam antibiotics, reversible leukopenia (neutropenia) is more apt to occur in patients receiving prolonged therapy at high dosages or in association with drugs known to cause this reaction.

Serum Electrolytes: Individuals with liver disease or individuals receiving cytotoxic therapy or diuretics were reported to demonstrate a decrease in serum potassium concentrations with high doses of piperacillin. Hypokalemia has been reported.

Skeletal: Prolonged muscle relaxation (see PRECAUTIONS, Drug Interactions).

Other: Fever, superinfection, including candidiasis; hemorrhagic manifestations have been reported.

Piperacillin therapy has been associated with an increased incidence of fever and rash in cystic fibrosis patients.